As is well known, many consumer electronics products include a remote control facility, typically using infrared communications but which may use radio frequency communications or other communications signals (including, for example, audio and ultrasonic signals), for use in controlling operation of the product. Such remote control generally includes an on/off control function, which is used to switch the product between a standby mode and a normal operating mode.
In the standby mode, power must be supplied to those parts of the product that are required to receive and respond to a remote control signal to switch the product to its operating mode. In the standby mode power may also be supplied for other functions, for example to maintain operation of clocks, timers, memory, and other features. The power used by the product in the standby mode is referred to as the standby power.
Although the standby power requirements of an individual consumer electronics product may be small compared with the operating power requirements, this standby power is consumed continuously, and there is a great number of such products, so that the total standby power consumption of such products is recognized as being very large.
Accordingly, there is a need for the standby power of individual consumer electronics products to be reduced to a very low level. For example, for some consumer electronics products (e.g. television receivers), maximum standby power requirements are specified by Energy Star® (www.energystar.gov) as being less than or equal to 1 watt. While such a low standby power can already be difficult to achieve for cost-sensitive products such as consumer electronics products, this maximum figure may be further reduced over time, and it is advantageous to reduce the standby power to well below this figure.
Additionally, such low standby power figures may be required to be met for a wide range of AC power supply voltages, for example in a range from about 90 to about 280 volts rms.
Typically, a consumer electronics product includes a standby power supply that is powered in the standby mode and provides power to the remote control receiver and to an associated microcontroller. The microcontroller is equipped with a mechanism to turn on one or more power supplies for normal operation of the product when a turn-on signal is produced by the user through the remote control. The standby power supply increases the cost of the product and also increases the standby power consumed by the product.
Accordingly, there is a need to provide an improved standby arrangement for use in consumer electronics products with a remote control receiver.